The effect of growth hormone on maturing or mature ruminants has been examined from time to time, but to date the administration of growth hormone within a finite period has not been recognized as useful in obtaining a permanent increase in milk production in a ruminant.
Peel et al, J. Nutrition, 1981, 111:1662-1671, describes the administration of bovine growth hormone to high yield cows and demonstrates that at peak milk production the administration growth hormone enhances milk production. Milk production returned to normal levels following cessation of the treatment.
Bauman et al, 1982, J. Diary Sci. 65 (Suppl.1):188, reported that recombinantly derived bovine growth hormone enhanced milk production and improved feed efficiency in a manner similar to the biological responses observed with natural bovine growth hormone.
Tucker, J. Dairy Sci., 1981, 64:1403-1421 inter alia discusses factors which affect mammary growth, including apparent interaction of estradiol-17.beta., progesterone, prolactin, growth hormone and placental lactogen to synergize to stimulate mammary growth.
Sejrsen, Acta Agric. Scandinavica, 1978, 28:41-45, discusses the fact that a major part of the development of the mammary glands takes place between birth and 1st calving and apparently is affected, in part, by growth hormone levels.
Bauman et al, 1979, J. Dairy Sci. 62 (Suppl. 1):114, describe the effect of energy intake upon serum concentrations of prolactin and growth hormone in lactating cows.
Sejrsen et al, Livestock Prod. Sci., 1977, 4:313-325, and J. Dairy Sci., 1982, 65:793-800 discuss the effect of nutrition on growth rate, mammary development and milk yield.